Field of the Invention
The present invention relates to a device for performing jobs on a surface with at least one work device that includes a device for generating an underpressure between itself and the surface, and a drive for moving on the surface, and that is connected to a base station by a supply line.
British Patent No. GB 2 268 457 A teaches such a device in which several work devices, which are held to a sloping or vertical surface by vacuum pressure and can be moved along this surface, are connected to a compressed air source and a control through a supply line. Over the supply line, a data exchange between the work devices and the control takes place, on one hand, and, on the other hand, the work devices are supplied with energy in the form of compressed air for the purpose of generating the underpressure. This type of device is also disclosed in U.S. Pat. No. 5,077,510 to Collie.
A particular disadvantage of these devices is that, if the vacuum pressure generator fails and can no longer hold them on the surface, the work devices, being unprotected, can fall off and can cause serious damage given utilization at great heights.
It is accordingly an object of the invention to provide a device for performing jobs on a surface with a base station that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that improves safety and, in particular, prevents falls from great heights.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for performing jobs on a surface, including at least one work device having a weight, vacuum generating device generating a holding force between the at least one work device and the surface, and a drive device for moving the at least one work device on the surface, a base station having a supply line connected to the at least one work device, and a safety line connecting the base station to the at least one work device, the safety line having a bearing capacity greater the weight of the at least one work device.
By virtue of the safety line between the base station and the at least one work device, the work device can only fall a limited distance in the event of a failure of the devices for holding onto the surface by suction. As such, the device can also be utilized on the outside of tall buildings without a risk of the work device falling and causing damage property or injuring persons at the foot of the building. If the work device on the outside of a building falls, it can only drop a limited distance corresponding to the length of the safety line, the invention being selected such that the work device cannot fall to the ground.
In accordance with another feature of the invention, to secure the work device, the base station has a larger mass and/or is provided with a device or means for anchoring itself at its environment. For instance, the base station can include non-slip feet or an extra clamp or line for anchoring at other objects. In particular, the base station has a mass approximately two to three times of a mass of the work device.
In accordance with a further feature of the invention, the base station has at least one energy device for storing and providing energy.
In accordance with an added feature of the invention, the base station advantageously contains a rechargeable battery with an appertaining charger and a current supply terminal. The overall device can, thus, be utilized with great flexibility, it being possible to achieve a particularly long operating period, given the ability to provide substantially larger batteries in the base station than would be possible in the work device, for which a low weight is desirable due to the energy-sapping vacuum adhesion mechanism.
Furthermore, the work device is supplied with at least one working medium through the supply line. For instance, if the at least one work device is utilized for cleaning the surface, a cleaning agent or cleaning liquid can be supplied over the supply line. Likewise, used working media such as used cleaning liquid can be drained off through the supply line.
In such a case, the base station includes devices for providing working media and devices for catching used working media. In preparation for use, the rechargeable battery is charged in the base station in that the base station is simply connected to the current supply network, and in that working media such as cleaning or rinsing liquids that are required for the work are refilled. To accomplish this, the work device need not be connected to the base station. The base station and the work device can then be moved to the working location and are ready for use after the safety line and supply line are connected as warranted.
The supplying of the work device with energy and/or with at least one working medium from a base station through a supply line is also possible regardless of a safety line.
In accordance with an additional feature of the invention, to prevent tangling of the supply line or safety line, devices for winding and unwinding the safety line and the supply line can be provided in the base station and/or the work device. These devices can be biased so that the lines are unwound as soon as the at least one work device is moved away from the base station and automatically rewound again when it is moved toward the base station again. The winding/rewinding also reduces the risk that objects will be pulled down by the safety line and/or the supply line or that the safety line and/or supply line will get hung up on objects when the work device is moved.
In accordance with a concomitant feature of the invention, the unwinding of the safety line can be braked or locked according to speed so that, in the event of a failure where the work device detaches, the fall is stopped with optimal speed, as with a safety harness.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for performing jobs on a surface with a base station, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.